RESUMO
Rett syndrome (RTT), mainly caused by mutations in methyl-CpG binding protein 2 (MeCP2), is one of the most prevalent intellectual disorders without effective therapies. Here, we used 2D and 3D human brain cultures to investigate MeCP2 function. We found that MeCP2 mutations cause severe abnormalities in human interneurons (INs). Surprisingly, treatment with a BET inhibitor, JQ1, rescued the molecular and functional phenotypes of MeCP2 mutant INs. We uncovered that abnormal increases in chromatin binding of BRD4 and enhancer-promoter interactions underlie the abnormal transcription in MeCP2 mutant INs, which were recovered to normal levels by JQ1. We revealed cell-type-specific transcriptome impairment in MeCP2 mutant region-specific human brain organoids that were rescued by JQ1. Finally, JQ1 ameliorated RTT-like phenotypes in mice. These data demonstrate that BRD4 dysregulation is a critical driver for RTT etiology and suggest that targeting BRD4 could be a potential therapeutic opportunity for RTT.
Assuntos
Azepinas/farmacologia , Encéfalo/patologia , Proteínas de Ciclo Celular/metabolismo , Interneurônios/patologia , Proteína 2 de Ligação a Metil-CpG/fisiologia , Síndrome de Rett/patologia , Fatores de Transcrição/metabolismo , Transcriptoma/efeitos dos fármacos , Triazóis/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Proteínas de Ciclo Celular/genética , Feminino , Células-Tronco Embrionárias Humanas/efeitos dos fármacos , Células-Tronco Embrionárias Humanas/metabolismo , Células-Tronco Embrionárias Humanas/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Interneurônios/efeitos dos fármacos , Interneurônios/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Fenótipo , Síndrome de Rett/tratamento farmacológico , Síndrome de Rett/genética , Síndrome de Rett/metabolismo , Fatores de Transcrição/genéticaRESUMO
Corrective feedback received on perceptual decisions is crucial for adjusting decision-making strategies to improve future choices. However, its complex interaction with other decision components, such as previous stimuli and choices, challenges a principled account of how it shapes subsequent decisions. One popular approach, based on animal behavior and extended to human perceptual decision-making, employs "reinforcement learning," a principle proven successful in reward-based decision-making. The core idea behind this approach is that decision-makers, although engaged in a perceptual task, treat corrective feedback as rewards from which they learn choice values. Here, we explore an alternative idea, which is that humans consider corrective feedback on perceptual decisions as evidence of the actual state of the world rather than as rewards for their choices. By implementing these "feedback-as-reward" and "feedback-as-evidence" hypotheses on a shared learning platform, we show that the latter outperforms the former in explaining how corrective feedback adjusts the decision-making strategy along with past stimuli and choices. Our work suggests that humans learn about what has happened in their environment rather than the values of their own choices through corrective feedback during perceptual decision-making.
Assuntos
Comportamento de Escolha , Tomada de Decisões , Animais , Humanos , Retroalimentação , Recompensa , Reforço PsicológicoRESUMO
Mutations in the Presenilin (PSEN1 and PSEN2) genes are the major cause of early-onset familial Alzheimer's disease (FAD). Presenilin (PS) is the catalytic subunit of the γ-secretase complex, which cleaves type I transmembrane proteins, such as Notch and the amyloid precursor protein (APP), and plays an evolutionarily conserved role in the protection of neuronal survival during aging. FAD PSEN1 mutations exhibit impaired γ-secretase activity in cell culture, in vitro, and knockin (KI) mouse brains, and the L435F mutation is the most severe in reducing γ-secretase activity and is located closest to the active site of γ-secretase. Here, we report that introduction of the codon-optimized wild-type human PSEN1 cDNA by adeno-associated virus 9 (AAV9) results in broadly distributed, sustained, low to moderate levels of human PS1 (hPS1) expression and rescues impaired γ-secretase activity in the cerebral cortex of Psen mutant mice either lacking PS or expressing the Psen1 L435F KI allele, as evaluated by endogenous γ-secretase substrates of APP and recombinant γ-secretase products of Notch intracellular domain and Aß peptides. Furthermore, introduction of hPS1 by AAV9 alleviates impairments of synaptic plasticity and learning and memory in Psen mutant mice. Importantly, AAV9 delivery of hPS1 ameliorates neurodegeneration in the cerebral cortex of aged Psen mutant mice, as shown by the reversal of age-dependent loss of cortical neurons and elevated microgliosis and astrogliosis. These results together show that moderate hPS1 expression by AAV9 is sufficient to rescue impaired γ-secretase activity, synaptic and memory deficits, and neurodegeneration caused by Psen mutations in mouse models.
Assuntos
Doença de Alzheimer , Secretases da Proteína Precursora do Amiloide , Humanos , Camundongos , Animais , Idoso , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Mutação , Transtornos da Memória/genética , Transtornos da Memória/terapia , Presenilina-2/genética , Peptídeos beta-Amiloides/metabolismoRESUMO
Intraneuronal inclusions of misfolded α-synuclein (α-syn) and prion-like spread of the pathologic α-syn contribute to progressive neuronal death in Parkinson's disease (PD). Despite the pathologic significance, no efficient therapeutic intervention targeting α-synucleinopathy has been developed. In this study, we provide evidence that astrocytes, especially those cultured from the ventral midbrain (VM), show therapeutic potential to alleviate α-syn pathology in multiple in vitro and in vivo α-synucleinopathic models. Regulation of neuronal α-syn proteostasis underlies the therapeutic function of astrocytes. Specifically, VM-derived astrocytes inhibited neuronal α-syn aggregation and transmission in a paracrine manner by correcting not only intraneuronal oxidative and mitochondrial stresses but also extracellular inflammatory environments, in which α-syn proteins are prone to pathologic misfolding. The astrocyte-derived paracrine factors also promoted disassembly of extracellular α-syn aggregates. In addition to the aggregated form of α-syn, VM astrocytes reduced total α-syn protein loads both by actively scavenging extracellular α-syn fibrils and by a paracrine stimulation of neuronal autophagic clearance of α-syn. Transplantation of VM astrocytes into the midbrain of PD model mice alleviated α-syn pathology and protected the midbrain dopamine neurons from neurodegeneration. We further showed that cografting of VM astrocytes could be exploited in stem cell-based therapy for PD, in which host-to-graft transmission of α-syn pathology remains a critical concern for long-term cell therapeutic effects.
Assuntos
Astrócitos , Transplante de Tecido Encefálico , Doença de Parkinson , Proteostase , alfa-Sinucleína , Animais , Astrócitos/transplante , Modelos Animais de Doenças , Neurônios Dopaminérgicos/metabolismo , Mesencéfalo/patologia , Mesencéfalo/cirurgia , Camundongos , Doença de Parkinson/patologia , Doença de Parkinson/terapia , alfa-Sinucleína/metabolismoRESUMO
Binary classification, an act of sorting items into two classes by setting a boundary, is biased by recent history. One common form of such bias is repulsive bias, a tendency to sort an item into the class opposite to its preceding items. Sensory-adaptation and boundary-updating are considered as two contending sources of the repulsive bias, yet no neural support has been provided for either source. Here, we explored human brains of both men and women, using functional magnetic resonance imaging (fMRI), to find such support by relating the brain signals of sensory-adaptation and boundary-updating to human classification behavior. We found that the stimulus-encoding signal in the early visual cortex adapted to previous stimuli, yet its adaptation-related changes were dissociated from current choices. Contrastingly, the boundary-representing signals in the inferior-parietal and superior-temporal cortices shifted to previous stimuli and covaried with current choices. Our exploration points to boundary-updating, rather than sensory-adaptation, as the origin of the repulsive bias in binary classification.SIGNIFICANCE STATEMENT Many animal and human studies on perceptual decision-making have reported an intriguing history effect called "repulsive bias," a tendency to classify an item as the opposite class of its previous item. Regarding the origin of repulsive bias, two contending ideas have been proposed: "bias in stimulus representation because of sensory adaptation" versus "bias in class-boundary setting because of belief updating." By conducting model-based neuroimaging experiments, we verified their predictions about which brain signal should contribute to the trial-to-trial variability in choice behavior. We found that the brain signal of class boundary, but not stimulus representation, contributed to the choice variability associated with repulsive bias. Our study provides the first neural evidence supporting the boundary-based hypothesis of repulsive bias.
Assuntos
Encéfalo , Tomada de Decisões , Masculino , Animais , Humanos , Feminino , Encéfalo/diagnóstico por imagem , Lobo Temporal , Percepção VisualRESUMO
BACKGROUND: Near-infrared fluorescence indocyanine green lymphangiography, a primary modality for detecting lymphedema, which is a disease due to lymphatic obstruction, enables real-time observations of lymphatics and reveals not only the spatial distribution of drainage (static analysis) but also information on the lymphatic contraction (dynamic analysis). METHODS: We have produced total lymphatic obstruction in the upper limbs of 18 Sprague-Dawley rats through the dissection of proximal (brachial and axillary) lymph nodes and 20-Gy radiation (dissection limbs). After the model formation for 1 week, 9 animal models were observed for 6 weeks using near-infrared fluorescence indocyanine green lymphangiography by injecting 6-µL ICG-BSA (indocyanine green-bovine serum albumin) solution of 20-µg/mL concentration. The drainage pattern and leakage of lymph fluid were evaluated and time-domain signals of lymphatic contraction were observed in the distal lymphatic vessels. The obtained signals were converted to frequency-domain spectrums using signal processing. RESULTS: The results of both static and dynamic analyses proved to be effective in accurately identifying the extent of lymphatic disruption in the dissection limbs. The static analysis showed abnormal drainage patterns and increased leakage of lymph fluid to the periphery of the vessels compared with the control (normal) limbs. Meanwhile, the waveforms were changed and the contractile signal frequency increased by 58% in the dynamic analysis. Specifically, our findings revealed that regular lymphatic contractions, observed at a frequency range of 0.08 to 0.13 Hz in the control limbs, were absent in the dissection limbs. The contractile regularity was not fully restored for the follow-up period, indicating a persistent lymphatic obstruction. CONCLUSIONS: The dynamic analysis could detect the abnormalities of lymphatic circulation by observing the characteristics of signals, and it provided additional evaluation indicators that cannot be provided by the static analysis. Our findings may be useful for the early detection of the circulation problem as a functional evaluation indicator of the lymphatic system.
Assuntos
Vasos Linfáticos , Linfedema , Animais , Ratos , Linfografia/métodos , Verde de Indocianina , Fluorescência , Ratos Sprague-Dawley , Vasos Linfáticos/diagnóstico por imagem , Vasos Linfáticos/patologia , Linfedema/diagnóstico por imagem , Linfedema/patologiaRESUMO
OBJECTIVES: To investigate whether machine learning (ML)-based center of pressure (COP) analysis for gait assessment, when used in conjunction with clinical information, offers additive benefits in predicting functional outcomes in patients with acute ischemic stroke. DESIGN: A prospective, single-center cohort study. SETTING: A tertiary hospital setting. PARTICIPANTS: A total of 185 patients with acute ischemic stroke, capable of walking 10 m with or without a gait aid by day 7 postadmission. From these patients, 10,804 pairs of consecutive footfalls were included for analysis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The dependent variable was a 3-month poor functional outcome, defined as modified Rankin scale score ≥2. For independent variables, 65 clinical variables including demographics, anthropometrics, comorbidities, laboratory data, questionnaires, and drug history were included. Gait function was evaluated using a pressure-sensitive mat. Time-series COP data were parameterized into spatial and temporal variables and analyzed with logistic regression and 2 ML models (light gradient-boosting machine and multilayer perceptron [MLP]). We derived GAIT-AI output scores from the best-performing model analyzed COP data and constructed multivariable logistic regression models using clinical variables and the GAIT scores. RESULTS: Among the included patients, 70 (37.8%) experienced unfavorable outcomes. The MLP model demonstrated the highest predictive performance with an area under the receiver operating characteristic curve (AUROC) of 0.799. Multivariable logistic regression identified age, initial National Institutes of Health Stroke Scale, and initial Fall Efficacy Scale-International as associated factors with unfavorable outcomes. The combined multivariable logistic regression incorporating COP-derived output scores improved the AUROC to 0.812. CONCLUSIONS: Gait function, assessed through COP analysis, serves as a significant predictor of functional outcome in patients with acute ischemic stroke. ML-based COP analysis, when combined with clinical data, enhances the prediction of poor functional outcomes.
RESUMO
INTRODUCTION: Accurately discerning periods of heightened risk of stroke or transient ischemic attack (TIA) recurrence and managing modifiable risk factors are essential for minimizing overall recurrence risk. This study identified differences in the timing of stroke or TIA recurrence based on risk factors and patient characteristics to develop strategies for reducing recurrence in clinical practice. METHODS: We retrospectively selected patients with ischemic stroke or TIA at the Korea University Ansan Hospital Stroke Center between March 2014 and December 2021 using the prospective institutional database of the Korea University Stroke Registry. We collected demographic, clinical data, and categorized participants by recurrence timing (early within or late after 3 months). Using multinomial logistic regression analysis, we examined variables associated with early and late recurrent stroke or TIAs. RESULTS: Among 3,646 patients, 255 experienced a recurrent stroke or TIA and 3,391 experienced their first stroke or TIA. Multinomial logistic regression analysis revealed significant associations between early recurrent stroke or TIA and diabetes mellitus (odds ratio [OR]: 1.98, 95% confidence interval [CI]: 1.25-3.15), other determined etiologies in the Trial of Org 10172 in the Acute Stroke Treatment classification (OR: 3.00, 95% CI: 1.37-6.61), and white matter changes (OR: 1.97, 95% CI: 1.17-3.33). Late recurrence showed a significant correlation with TIA (OR: 2.95, 95% CI: 1.52-5.71) and cerebral microbleeds (OR: 2.22, 95% CI: 1.32-3.75). CONCLUSION: Substantial differences in factors contribute to stroke or TIA recurrence based on timing. Managing the risk of recurrence in clinical practice necessitates accurate identification of heightened risk periods and rigorous control of modifiable risk factors.
RESUMO
BACKGROUND: The demand for organ transplants, both globally and in South Korea, substantially exceeds the supply, a situation that might have been aggravated by the enactment of the Life-Sustaining Treatment Decision Act (LSTDA) in February 2018. This legislation may influence emergency medical procedures and the availability of organs from brain-dead donors. This study aimed to assess LSTDA's impact, introduced in February 2018, on organ donation status in out-of-hospital cardiac arrest (OHCA) patients in a metropolitan city and identified related factors. METHODS: We conducted a retrospective analysis of a regional cardiac arrest registry. This study included patients aged 16 or older with cardiac arrest and a cerebral performance category (CPC) score of 5 from January 2015 to December 2022. The exclusion criteria were CPC scores of 1-4, patients under 16 years, and patients declared dead or transferred from emergency departments. Logistic regression analysis was used to analyse factors affecting organ donation. RESULTS: Of the 751 patients included in this study, 47 were organ donors, with a median age of 47 years. Before the LSTDA, there were 30 organ donations, which declined to 17 after its implementation. In the organ donation group, the causes of cardiac arrest included medical (34%), hanging (46.8%), and trauma (19.2%). The adjusted odds ratio for organ donation before the LSTDA implementation was 6.12 (95% CI 3.09-12.12), with non-medical aetiology as associated factors. CONCLUSION: The enactment of the LSTDA in 2018 in South Korea may be linked to reduced organ donations among patients with OHCA, underscoring the need to re-evaluate the medical and legal aspects of organ donation, especially considering end-of-life care decisions.
Assuntos
Parada Cardíaca Extra-Hospitalar , Obtenção de Tecidos e Órgãos , Humanos , Parada Cardíaca Extra-Hospitalar/terapia , Parada Cardíaca Extra-Hospitalar/mortalidade , República da Coreia/epidemiologia , Obtenção de Tecidos e Órgãos/legislação & jurisprudência , Estudos Retrospectivos , Masculino , Pessoa de Meia-Idade , Feminino , Adulto , Idoso , Tomada de Decisões , Doadores de Tecidos/legislação & jurisprudência , Cuidados para Prolongar a Vida/legislação & jurisprudência , Cuidados para Prolongar a Vida/ética , Sistema de RegistrosRESUMO
BACKGROUND: With the growing demand for the use of thin perforator flaps, obtaining knowledge on the superficial anatomy of perforators is imperative for stable flap elevation. Conventional modalities for perforator mapping fall short in providing such information. High-frequency ultrasound (HFUS), known for visualizing the superficially located anatomic structures, may potentially fill this void. This study aimed to evaluate the effectiveness of HFUS in the outcome of anterolateral thigh (ALT) and superficial circumflex iliac artery perforator (SCIP) flap-based reconstructions. METHODS: Consecutive patients who underwent free ALT or SCIP flap-based reconstruction from January 2021 to November 2022 were retrospectively reviewed. Perforator mapping was conducted using a handheld Doppler during the first year, while HFUS was used in the latter part. The two techniques were compared in terms of flap harvesting time and perfusion-related complication rates while considering the flap elevation plane. RESULTS: In total, 123 cases were analyzed, including 82 ALT flaps (41 in each group) and 41 SCIP flaps (16 in the Doppler and 25 in the HFUS group). The time required for flap elevation exhibited a tendency to decrease in the HFUS group, with a significant difference observed in cases involving thin flap elevation (super-thin ALT flaps and pure-skin-perforator SCIP flaps). Compared with the Doppler group, the HFUS group demonstrated significantly lower rates of PRCs, particularly partial flap necrosis. This difference remained significant in multivariable analyses. CONCLUSION: Our results suggest that HFUS might be an appealing modality for perforator mapping in cases requiring thin ALT and SCIP flap.
Assuntos
Retalho Perfurante , Procedimentos de Cirurgia Plástica , Humanos , Retalho Perfurante/irrigação sanguínea , Coxa da Perna/cirurgia , Coxa da Perna/irrigação sanguínea , Artéria Ilíaca/cirurgia , Estudos RetrospectivosRESUMO
Excitons, electron-hole pairs in semiconductors, can be utilized as information carriers with a spin or valley degree of freedom. However, manipulation of excitons' motion is challenging because of their charge-neutral characteristic and short recombination lifetimes. Here we demonstrate electric-field-driven drift and funneling of charged excitons (i.e., trions) toward the center of a MoSe2 monolayer. Using a simple bottom-gate device, we control the electric fields in the vicinity of the suspended monolayer, which increases the trion density and pulls down the layer. We observe that locally excited trions are subjected to electric force and, consequently, drift toward the center of the stretched layer. The exerting electric force on the trion is estimated to be 102-104 times stronger than the strain-induced force in the stretched monolayer, leading to the successful observation of trion drift under continuous-wave excitation. Our findings provide a new route for manipulating trions and achieving new types of optoelectronic devices.
RESUMO
A promising de novo approach for the treatment of Castration-resistant prostate cancer (CRPC) exploits cell-mediated enzyme prodrug therapy comprising cytosine deaminase (CD) and fluorouracil (5-FC). The aim of this study was to determine the potential of bacterial CD-overexpressing hTERT-immortalized human adipose stem cells (hTERT-ADSC.CD) to suppress CRPC. A lentiviral vector encoding a bacterial CD gene was used to transfect and to generate the hTERT-ADSC.CD line. The ability of the cells to migrate selectively towards malignant cells was investigated in vitro. PC3 and hTERT-ADSC.CD cells were co-cultured. hTERT-ADSC.CD and 1 × 106 PC3 cells were administered to nude mice via intracardiac and subcutaneous injections, respectively, and 5-FC was given for 14 days. hTERT-ADSC.CD were successfully engineered. Enhanced in vitro hTERT-ADSC.CD cytotoxicity and suicide effect were evident following administration of 5 µM 5-FC. hTERT-ADSC.CD, together with 5-FC, augmented the numbers of PC3 cells undergoing apoptosis. In comparison to controls administered hTERT-ADSC.CD monotherapy, hTERT-ADSC.CD in combination with 5-FC demonstrated a greater suppressive effect on tumor. In CPRC-bearing mice, tumor suppression was enhanced by the combination of CD-overexpressing ADSC and the prodrug 5-FC. Stem cells exhibiting CD gene expression are a potential novel approach to treatment for CRPC.
Assuntos
Citosina Desaminase , Flucitosina , Neoplasias de Próstata Resistentes à Castração , Telomerase , Animais , Humanos , Masculino , Camundongos , Tecido Adiposo/citologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citosina Desaminase/genética , Citosina Desaminase/metabolismo , Flucitosina/farmacologia , Camundongos Nus , Células PC-3 , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/terapia , Células-Tronco , Telomerase/genética , Telomerase/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Global public health is facing a major issue with emerging resistance to antimicrobial agents. Antimicrobial agents that are currently on the market are strong and efficient, but it has not been ruled out that these medications will eventually cause resistance to bacteria. Exploring novel bioactive compounds derived from natural sources is therefore, crucial to meet future demands. The present study evaluated the mode of action of the antimicrobial potential protease enzyme SH21. Protease SH21 exhibited antimicrobial activity, strong heat stability (up to 100 °C), and pH stability (pH 3.0 to 9.0). In terms of mode of action, we found that protease SH21 was able to disrupt the bacterial cell membrane as the results of the nucleotide leakage and cell membrane permeability assay. In addition, we also checked inner membrane permeability by PI uptake assay which suggested that protease SH21 has the ability to enter the bacterial cell membrane. Our results revealed that the antimicrobial protease SH21 might be a promising candidate for treating microbial infections.
Assuntos
Bacillus , Testes de Sensibilidade Microbiana , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Peptídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antibacterianos/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Estabilidade EnzimáticaRESUMO
Background and Objectives: The association between neurological disability, prognosis, and telomere length (TL) in patients with stroke has been investigated in various ways. However, analysis of the type of stroke and ischemic stroke subgroups is limited. In this study, we aimed to determine the association between TL and neurological disability according to stroke type. Materials and Methods: This prospective study included patients with stroke who visited a single-center emergency department (ED) between January 2022 and December 2023. The association between TL and neurological disabilities, using the Modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS), was evaluated according to the patient's stroke type and subgroup of ischemic stroke. Multivariate analysis was performed to determine the association between neurological disabilities in patients with ischemic stroke and the subgroups. Results: A total of 271 patients with stroke were enrolled. The NIHSS score was found to be higher at the time of ED visit (adjusted odds ratio [OR], 5.23; 95% confidence interval [CI], 1.59-17.2, p < 0.01) and 1 day later (adjusted OR, 7.78; 95% CI, 1.97-30.70, p < 0.01) in the ischemic stroke group with a short TL. In the other determined etiology (OD) or undetermined etiology (UD) group, the NIHSS was higher in the short TL group at the ED visit (adjusted OR, 7.89; 95% CI, 1.32-47.25, p = 0.02) and 1 day after (adjusted OR, 7.02; 95% CI, 1.14-43.47, p = 0.04). Conclusions: TL is associated with neurological disability in early ischemic stroke and is prominent in the UD and OD subgroups.
Assuntos
Acidente Vascular Cerebral , Humanos , Feminino , Masculino , Estudos Prospectivos , Idoso , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/genética , Telômero , AVC Isquêmico/complicações , AVC Isquêmico/genética , AVC Isquêmico/fisiopatologia , Avaliação da Deficiência , Prognóstico , Pessoas com Deficiência/estatística & dados numéricos , Idoso de 80 Anos ou maisRESUMO
Post-traumatic epilepsy (PTE) and behavioral comorbidities frequently develop after traumatic brain injury (TBI). Aberrant neurogenesis of dentate granule cells (DGCs) after TBI may contribute to the synaptic reorganization that occurs in PTE, but how neurogenesis at different times relative to the injury contributes to feedback inhibition and recurrent excitation in the dentate gyrus is unknown. Thus, we examined whether DGCs born at different postnatal ages differentially participate in feedback inhibition and recurrent excitation in the dentate gyrus using the controlled cortical impact (CCI) model of TBI. Both sexes of transgenic mice expressing channelrhodopsin2 (ChR2) in postnatally born DGCs were used for optogenetic activation of three DGC cohorts: postnatally early born DGCs, or those born just before or after CCI. We performed whole-cell patch-clamp recordings from ChR2-negative, mature DGCs and parvalbumin-expressing basket cells (PVBCs) in hippocampal slices to determine whether optogenetic activation of postnatally born DGCs increases feedback inhibition and/or recurrent excitation in mice 8-10 weeks after CCI and whether PVBCs are targets of ChR2-positive DGCs. In the dentate gyrus ipsilateral to CCI, activation of ChR2-expressing DGCs born before CCI produced increased feedback inhibition in ChR2-negative DGCs and increased excitation in PVBCs compared with those from sham controls. This upregulated feedback inhibition was less prominent in DGCs born early in life or after CCI. Surprisingly, ChR2-positive DGC activation rarely evoked recurrent excitation in mature DGCs from any cohort. These results support that DGC birth date-related increased feedback inhibition in of DGCs may contribute to altered excitability after TBI.SIGNIFICANCE STATEMENT Dentate granule cells (DGCs) control excitability of the dentate gyrus through synaptic interactions with inhibitory GABAergic interneurons. Persistent changes in DGC synaptic connectivity develop after traumatic brain injury, contributing to hyperexcitability in post-traumatic epilepsy (PTE). However, the impact of DGC neurogenesis on synaptic reorganization, especially on inhibitory circuits, after brain injury is not adequately described. Here, upregulation of feedback inhibition in mature DGCs from male and female mice was associated with increased excitation of parvalbumin-expressing basket cells by postnatally born DGCs, providing novel insights into underlying mechanisms of altered excitability after brain injury. A better understanding of these inhibitory circuit changes can help formulate hypotheses for development of novel, evidence-based treatments for post-traumatic epilepsy by targeting birth date-specific subsets of DGCs.
Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas , Epilepsia Pós-Traumática , Animais , Giro Denteado/fisiologia , Modelos Animais de Doenças , Retroalimentação , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Parvalbuminas , Regulação para CimaRESUMO
Parkinson's disease (PD) is neurodegenerative movement disorder characterized by degeneration of midbrain-type dopamine (mDA) neurons in the substantia nigra (SN). The RNA-binding protein Lin28 plays a role in neuronal stem cell development and neuronal differentiation. In this study, we reveal that Lin28 conditional knockout (cKO) mice show degeneration of mDA neurons in the SN, as well as PD-related behavioral deficits. We identify a loss-of-function variant of LIN28A (R192G substitution) in two early-onset PD patients. Using an isogenic human embryonic stem cell (hESC)/human induced pluripotent stem cell (hiPSC)-based disease model, we find that the Lin28 R192G variant leads to developmental defects and PD-related phenotypes in mDA neuronal cells that can be rescued by expression of wild-type Lin28A. Cell transplantation experiments in PD model rats show that correction of the LIN28A variant in the donor patient (pt)-hiPSCs leads to improved behavioral phenotypes. Our data link LIN28A to PD pathogenesis and suggest future personalized medicine targeting this variant in patients.
Assuntos
Doença de Parkinson/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/fisiologia , Substância Negra/metabolismo , Animais , Comportamento Animal , Transplante de Células , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/fisiologia , Células-Tronco Embrionárias/fisiologia , Edição de Genes , Predisposição Genética para Doença , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Células-Tronco Pluripotentes Induzidas/transplante , Camundongos , Camundongos Knockout , Mutação , Células-Tronco Neurais/fisiologia , Células-Tronco Neurais/transplante , Doença de Parkinson/genética , Ratos , Transplante de Células-TroncoRESUMO
OBJECTIVE: Obesity has traditionally been considered a risk factor for ischemic stroke. However, some clinical observations have reported a complex relationship between patients who are overweight or obese with paradoxically better stroke outcomes. Stroke subtypes have differing distributions of risk factors, so this study aimed to explain the relationship between body mass index (BMI) and functional prognosis according to stroke subtype. METHODS: A prospective institutional database on stroke was accessed between March 2014 and December 2021, and consecutive patients with ischemic stroke were retrospectively selected. BMI was categorized into five groups (underweight, normal weight, overweight, obese, and morbid obesity). The outcome of interest in this study was the modified Rankin Scale (mRS) at 90 d, which was divided into favorable (mRS = 0-2) and unfavorable (mRS ≥ 3) groups. The relationship between functional outcome and BMI was analyzed according to stroke subtype. RESULTS: Among 2779 patients with stroke, 913 (32.9%) had unfavorable outcomes. After a propensity score-matched analysis, obesity was inversely associated with unfavorable outcomes (adjusted odds ratio [aOR] = 0.61, 95% confidence interval [95% CI]: 0.46-0.80) in all patients with stroke. Among the stroke subtypes, overweight (aOR = 0.38, 95% CI: 0.20-0.74) and obese (aOR = 0.40, 95% CI: 0.21-0.76) groups were inversely associated with unfavorable outcomes in the cardioembolism subtype. Obesity (aOR = 0.55, 95% CI: 0.32-0.95) was inversely associated with unfavorable outcomes in the small vessel disease subtype. There was no significant relationship between stroke outcome and BMI classification in the large artery disease subtype. CONCLUSIONS: These findings suggest that the obesity paradox in ischemic stroke outcomes might differ according to the stroke subtype.
Assuntos
AVC Isquêmico , Obesidade Mórbida , Acidente Vascular Cerebral , Humanos , Sobrepeso , Estudos Prospectivos , Estudos Retrospectivos , Paradoxo da Obesidade , Pontuação de Propensão , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Índice de Massa Corporal , Fatores de Risco , Obesidade Mórbida/complicações , AVC Isquêmico/complicações , Resultado do TratamentoRESUMO
Glioblastoma is one of the most malignant primary brain cancer. Despite surgical resection with modern technology followed by chemo-radiation therapy with temozolomide, resistance to the treatment and recurrence is common due to its aggressive and infiltrating nature of the tumor with high proliferation index. The median survival time of the patients with glioblastomas is less than 15 months. Till now there has been no report of molecular target specific for glioblastomas. Early diagnosis and development of molecular target specific for glioblastomas are essential for longer survival of the patients with glioblastomas. Development of biomarkers specific for glioblastomas is most important for early diagnosis, estimation of the prognosis, and molecular target therapy of glioblastomas. To that end, in this study, we have conducted a comprehensive proteome study using primary cells and tissues from patients with glioblastoma. In the discovery stage, we have identified 7429 glioblastoma-specific proteins, where 476 proteins were quantitated using Tandem Mass Tag (TMT) method; 228 and 248 proteins showed up and down-regulated pattern, respectively. In the validation stage (20 selected target proteins), we developed quantitative targeted method (MRM: Multiple reaction monitoring) using stable isotope standards (SIS) peptide. In this study, five proteins (CCT3, PCMT1, TKT, TOMM34, UBA1) showed the significantly different protein levels (t-test: p value ≤ 0.05, AUC ≥ 0.7) between control and cancer groups and the result of multiplex assay using logistic regression showed the 5-marker panel showed better sensitivity (0.80 and 0.90), specificity (0.92 and 1.00), error rate (10 and 2%), and AUC value (0.94 and 0.98) than the best single marker (TOMM34) in primary cells and tissues, respectively. Although we acknowledge that the model requires further validation in a large sample size, the 5 protein marker panel can be used as baseline data for the discovery of novel biomarkers of the glioblastoma.
RESUMO
Midbrain dopamine (DA) neurons are associated with locomotor and psychiatric disorders. DA phenotype is specified in ancestral neural precursor cells (NPCs) and maintained throughout neuronal differentiation. Here we show that endogenous expression of MeCP2 coincides with DA phenotype specification in mouse mesencephalon, and premature expression of MeCP2 prevents in vitro cultured NPCs from acquiring DA phenotype through interfering NURR1 transactivation of DA phenotype genes. By contrast, ectopic MeCP2 expression does not disturb DA phenotype in the DA neurons. By analyzing the dynamic change of DNA methylation along DA neuronal differentiation at the promoter of DA phenotype gene tyrosine hydroxylase (Th), we show that Th expression is determined by TET1-mediated de-methylation of NURR1 binding sites within Th promoter. Chromatin immunoprecipitation assays demonstrate that premature MeCP2 dominates the DNA binding of the corresponding sites thereby blocking TET1 function in DA NPCs, whereas TET1-mediated de-methylation prevents excessive MeCP2 binding in DA neurons. The significance of temporal DNA methylation status is further confirmed by targeted methylation/demethylation experiments showing that targeted de-methylation in DA NPCs protects DA phenotype specification from ectopic MeCP2 expression, whereas targeted methylation disturbs phenotype maintenance in MeCP2-overexpressed DA neurons. These findings suggest the appropriate timing of MeCP2 expression as a novel determining factor for guiding NPCs into DA lineage.
Assuntos
Neurônios Dopaminérgicos , Proteína 2 de Ligação a Metil-CpG , Células-Tronco Neurais , Animais , Camundongos , Diferenciação Celular/genética , Neurônios Dopaminérgicos/metabolismo , Mesencéfalo , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Células-Tronco Neurais/metabolismo , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Fenótipo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
There is a compelling need to develop disease-modifying therapies for Alzheimer's disease (AD), the most common neuro-degenerative disorder. Together with recent progress in vector development for efficiently targeting the central nervous system, gene therapy has been suggested as a potential therapeutic modality to overcome the limited delivery of conventional types of drugs to and within the damaged brain. In addition, given increasing evidence of the strong link between glia and AD pathophysiology, therapeutic targets have been moving toward those addressing glial cell pathology. Nurr1 and Foxa2 are transcription/epigenetic regulators that have been reported to cooperatively regulate inflammatory and neurotrophic response in glial cells. In this study, we tested the therapeutic potential of Nurr1 and Foxa2 gene delivery to treat AD symptoms and pathologies. A series of functional, histologic, and transcriptome analyses revealed that the combined expression of Nurr1 and Foxa2 substantially ameliorated AD-associated amyloid ß and Tau proteinopathy, cell senescence, synaptic loss, and neuro-inflammation in multiple in vitro and in vivo AD models. Intra-cranial delivery of Nurr1 and Foxa2 genes using adeno-associated virus (AAV) serotype 9 improved the memory and cognitive function of AD model mice. The therapeutic benefits of gene delivery were attained mainly by correcting pathologic glial function. These findings collectively indicate that AAV9-mediated Nurr1 and Foxa2 gene transfer could be an effective disease-modifying therapy for AD.